Set up and troubleshoot the standards that prove your mail is really yours — SPF, DKIM, DMARC, BIMI, MTA-STS, ARC, TLS-RPT, reverse DNS and MX records. Beginner and advanced guides, troubleshooting walkthroughs, and best practices that meet the latest Google, Yahoo and Microsoft sender requirements.
This ToolTrusted study breaks down DMARC adoption by TLD — measured from live DNS across the top 10,000 domains in the Majestic Million in June 2026. Headline averages hide enormous variation: depending on the top-level domain, the share of sites that actually enforce DMARC ranges from 11.0% to 79.0%. Looking at DMARC adoption by TLD … Read more
Choosing the best DMARC software is really about choosing how much you want a tool to do for you: parse the raw XML reports your domain receives, identify which services are sending as you, and guide you safely from monitoring to full enforcement. The best DMARC software turns a flood of unreadable aggregate reports into … Read more
DNSSEC (DNS Security Extensions) cryptographically signs your DNS records so that resolvers can prove the answers they receive are authentic and unaltered. For email, that matters more than it first appears: every modern email-authentication mechanism — SPF, DKIM, DMARC, MX, MTA-STS, TLS-RPT and BIMI — lives in DNS, and DNSSEC is what stops an attacker … Read more
This ToolTrusted study reports original email authentication statistics measured from live DNS across 10,000 of the world’s most-linked domains in June 2026. We wanted to answer a simple question with hard data instead of guesswork: now that Google, Yahoo and Microsoft require bulk senders to authenticate, how many domains have actually done it — and … Read more
A BIMI record is the DNS entry that can put your brand’s logo next to your messages in supporting inboxes — the blue-checkmark, logo-in-the-avatar treatment you have seen from big senders. BIMI (Brand Indicators for Message Identification) is not an authentication method itself; it is a display layer that rides on top of an enforced … Read more
ARC email authentication — the Authenticated Received Chain — exists to solve one frustrating problem: legitimate mail that fails DMARC after it passes through a mailing list or forwarder. When an intermediary modifies a message or relays it from a new IP, it breaks SPF and DKIM, so DMARC fails even though the mail was … Read more
TLS-RPT is the reporting layer that tells you when encrypted email delivery to your domain succeeds or fails. If you have deployed — or plan to deploy — MTA-STS or DANE to enforce TLS, you have a blind spot: when a sender cannot establish a secure connection and a message is delayed or refused, that … Read more
MTA-STS lets your domain require that other mail servers use encrypted, authenticated TLS when they deliver email to you. Without it, the encryption between mail servers is merely opportunistic — an attacker can strip it away and force your mail into plain text without anyone noticing. MTA-STS closes that gap by publishing a policy that … Read more
Reverse DNS maps an IP address back to a hostname, and for email it is one of the quiet make-or-break signals of whether your mail is trusted or blocked. Where forward DNS turns a name into an IP, reverse DNS does the opposite using a PTR record, and mailbox providers check it on every connection. … Read more
An MX record is the DNS entry that tells the rest of the internet which servers accept email for your domain. Every message sent to an address at your domain is routed by its MX record, which makes it the foundation of inbound mail — get it wrong and you simply stop receiving email. This … Read more